Industry increasingly depends upon highly automated data-acquisition and control systems to ensure that industrial processes run efficiently and reliably while lowering overall production costs. Data acquisition begins when sensors measure aspects of an industrial process and report their measurements back to a data-collection and control system. Such measurements could include, for example, temperature, pressure, pH, mass or volume flow of a material, count of items passing through a particular machine or process, and tallied inventory of packages waiting in a shipping line. Sophisticated process-management software examines the incoming measurements, produces status reports and operation summaries, and, in many cases, responds to events and operator instructions by sending commands to controllers that modify operation of at least a portion of the industrial process. These systems of sensors, controllers, and process-management software together allow operators to perform a number of supervisory tasks including tailoring the process in response to varying external conditions, detecting an inefficient or non-optimal operating condition or impending equipment failure, and taking remedial action such as moving equipment into and out of service.
To allow human operators to keep up with a sophisticated industrial process, human-machine interface (“HMI”) systems are linked to the data sources, digest their data measurements, and in turn drive visualization applications that render graphical views of the industrial process for the operators. A typical HMI includes a set of graphical views of the industrial process and of its physical output. Each view, in turn, includes one or more graphical elements. Some graphical elements are “animated” in that their display state changes in response to changes in the incoming data measurements. For example, an HMI for a refining process could include a visual depiction of a storage tank. The tank's depiction includes an indicator showing the level of liquid contained in the tank, and the visual indicator rises and falls in response to measurements from a sensor that measures the level of liquid in the actual tank. This type of animation has been found to be considerably easier for a human observer to comprehend than a simple stream of measurements. Graphical images provided by HMI applications are also used to depict, and to facilitate modifying, current process set points.
Typically, the physical sensors and controllers of the industrial process are linked to the HMI by a set of software modeling elements called automation objects. Several vendors offer software for automation control, from automation objects tailored to specific physical sensors and controllers (often manufactured by the same vendor that offers the automation objects), to development environments and databases for managing the automation objects, to full HMI-based supervisory and control systems. Typically, each vendor publishes a set of standards with which developers must comply in order to work with that vendor's offerings. These standards can define, for example, object templates, object interfaces, data, methods, scripts, and commands for developing objects, for deploying the objects into a coherent system, and for operating an enterprise-wide industrial process.